Apple Patches Shellshock as Attacks Continue

Five days after the Shellshock vulnerability in the Bash (Bourne Again SHell) shell scripting application was first publicly reported, Apple is finally providing a fix for Mac OS X users.

It's about time.

The Shellshock flaw came to light on Sept. 24 and was first associated with a vulnerability identified as CVE-2014-6271. The scope of the flaw within Bash has since been expanded to include other identified vulnerabilities, including CVE-2014-7169. Apple's patch fixes both the CVE-2014-6271 and CVE-2014-7169 issues.

"In certain configurations, a remote attacker may be able to execute arbitrary shell commands," Apple warned in its advisory.

The root cause of the Shellshock flaw is weakness in how Bash is able to parse certain environment variables, which could enable an attacker to exploit a system.

Apple's advisory noted that its patch for Shellshock now provides "improved environment variable parsing, by better detecting the end of the function statement."

The Apple Shellshock patch is available for the OS X 10.7.5, 10.8.5 and 10.9.5 releases. Apple is currently gearing up for its next major release, 10.10 (code-named Yosemite), which will have the patched version of Bash when it ships.

Shellshock's impact comes across all Unix and Linux systems that use Bash. While that might not seem to include Apple's Mac OX, it's important to remember that since 2007, Apple's OS X has been officially considered a Unix-based operating system.

As to why Apple took several days to patch the issue, there likely are several reasons. For one, Apple is typically a little behind the open-source community in terms of patching. The other issue is that with Shellshock, the actual vulnerability is somewhat complex and I suspect that Apple wanted to make sure it covered all its bases.

That said, Apple potentially left its customers exposed for days while attacks have proliferated around the Internet. However, the reality is that the risk to Mac OS X users is likely minimal, as attacks seem to be concentrated on servers and not end-user systems.

Security firm Incapsula reported on Sept. 29 that since news of the Shellshock vulnerability first broke on Sept. 24, it had seen 217,089 exploit attempts against its Web Application Firewall customers. The attacks are also broadly based, with more than 890 different IP addresses launching Shellshock-related attacks.

The simple truth of a flaw like Shellshock is that it takes time for systems to be updated, whether those systems are servers or Mac OS X desktops. There will likely be a significant volume of Shellshock-related attack traffic and breaches for weeks and possibly months to come.

Sean Michael Kerner is a senior editor at eWEEK and InternetNews.com. Follow him on Twitter @TechJournalist.